Virus
An infectious particle made only of a strand of DNA or RNA surrounded by a protein coat.
Viruses, bacteria, viroids, and prions
What causes infection?
A virus is a particle made only of a strand of DNA or RNA, while bacteria are one-celled microorganisms. This is how they differ. Both can cause infections, which was previously stated in the question.
Viruses and Bacteria both cause infections, but how are they different?
Pathogen
Any living organism or particle that can cause an infectious disease. It is also called an infectious agent.
viruses respond to their environments, have genes, and can reproduce
How are viruses like living cells?
viruses, unlike living cells, cannot reproduce on their own
How are viruses unlike living cells?
Viroids
Infectious particles that cause disease in plants. They are made of single-stranded RNA without a protein coat, and are passed through seeds or pollen.
Viroids impact agriculture, because they can stunt the growth of plants.
How do viroids impact agriculture?
Prion
An infectious particle made only of proteins that can cause other proteins to fold incorrectly.
Prions are unusual because they are infectious yet have no genetic material.
How are prions unusual?
Capsid
The protein shell which surrounds the genetic material of a virion, a signal viral particle.
lipid envelope
the protective outer coat of a virus, from which spiky structures of proteins and sugars may stick out
enveloped, helical, polyhedral
What are three common viral shapes?
A virus can have either DNA or RNA, but it can never have both.
What can viruses have either of, but never both?
Bacteriophages
viruses that infect bacteria
They differ in their methods of entering the host cell. Bacteriophages pierce the host cell and eukaryotic viruses enter by endocytosis and also fuse with membrane.
How do viruses that infect Eukaryotes differ from Bacteriophages?
The lytic infection is an infection pathway in which the host cell bursts, releasing the new viral offspring into the host's system, where each then infects another cell. In the lysogenic infection, a phage combines its DNA into the host cell's DNA.
Describe the two types of infections viruses cause.
Prophage
The phage DNA inserted into the host cell's DNA. In organisms other than bacteria, this is called a provirus.
A virus must pass through the skin of a vertebrate in order to enter its host.
In a vertebrate what is the first obstacle a virus must pass to enter its host?
Outer skeleton and tough cell wall
What is the first defense on non-vertebrates against viruses?
The common cold, Influenza, SARS, HIV
What are some common Viral infections?
Epidemic
A rapid outbreak of an infection that affects many people.
Pandemic
Disease that occurs over a wide geographic area and affects a very high proportion of the population.
Vaccine
A substance that stimulates the body's own immune response against invasion by microbes.
weakened pathogens
What are vaccines made from?
vaccine
The only way to control the spread of a viral disease
Retro virus
A virus that contains RNA and uses an enzyme called reverse transcriptase to make a DNA copy.
Single-celled prokaryotes
Bacteria and Archaea are both...
Earth
Prokaryotes are widespread on...
Oxygen
Prokaryotes are grouped by their need for...
Obligate Anaerobe
Prokaryotes which are poisoned by oxygen
Obligate Aerobes
prokaryotes that need oxygen to live
Facultative aerobe
prokaryote that can survive with or without oxygen
lactobacilli: rod shaped, Spirochaeta: spiral, and Entercocci: spherical
What are the three most common forms of Bacteria?
Plasmid
A small piece of genetic material that can replicate separately from the prokaryote's main chromosome.
Flagellum
A long, whip like structure outside of a cell that is used for movement.
Pili
Appendages that allow bacteria to attach to each other and to transfer DNA
Molecular differences
How are bacteria and archaea different
Peotidoglycan
The amount of ______ within the cell wall can differ between bacteria.
gram positive
Describing the group of bacteria that have a cell wall that is structurally less complex and contains more peptidoglycan.
gram negative
Describing the group of bacteria that have a cell wall that is structurally more complex and contains less peptidoglycan.
Gram staining
Used to identify the 2 types of bacteria- those with and those without an outer layer of lipid
Gram positive, more peptidoglycan
_____ stains purple, _____
gram negative, less peptidoglycan
______ stains pink, ______
binary fission
type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells
Conjugation
process by which a prokaryote transfers part of its chromosome to another prokaryote by forming a hollow bridge of pili
Endospore
A specialized cell with a thick, protective wall that forms during unfavorable conditions
Prokaryotes keep away harmful microbes by filling niches that might otherwise be filled with disease causing bacteria, make vitamins and other compounds, and break down food.
What are two ways in which pokaryotes that live within our bodies are helpful to us?
Nutrients
What do prokaryotes proves to humans and other animals?
mutualistic symbiosis
Relationship between bacteria and it's host
Food and a home with a stable pH and temp
What does the host provide for bacteria?
photosynthesize; recycle carbon, nitrogen, and sulfur, fix nitrogen; and bioremediation to break down oil spills and biodegradable materials
Describe some ways Prokaryotes play important roles in ecosystems....
Bioremediation
A process that uses microbes and other living things to break down pollutants.
Understanding bacteria
What is necessary in order to prevent and treat disease?
Invading tissues or making toxins
How do bacteria cause disease?
Toxin
A poison released by an organism.
By invading the tissues and attacking cells or by making poisons, or toxins that can be carried by blood to sites throughout the body.
What are two ways Bacteria can cause illness to the host?
Tuberculosis, Food Poisoning, Acne, Anthrax, Lyme Disease, Tetanus, Tooth decay
What are some common bacterial infections?
Antibiotics
Chemicals that kill or slow the growth of bacteria by stoping bacterial cell wall formation
Prevention
Since antibiotics don't work on viruses, what is the best method to fight bacterial disease?
Complete wipeout if the community of intestinal microbes resulting in illness
What can the overuse of antibiotics cause?
overuse, underuse, misuse
when does bacteria become resistant to antibiotics
Multidrug-resistant bacteria, happens as a result of natural selection, as individuals who are more resistant are more likely to survive and reproduce.
How can bacteria evolve to resist antibiotics?